Morphological Variation in Bearded Tomb Bats (Taphozous) in Maluku Tenggara and Nusa Tenggara Timur, Indonesia
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Records of the Western Australian Museum 17: 213-220 (1995). Morphological variation in Bearded Tomb Bats (Taphozous) in Maluku Tenggara and Nusa Tenggara Timur, Indonesia D.J. Kitchenerl and A. Suyanto2 1 Western Australian Museum, Francis Street, Perth, Western Australia 6000 2 Balitbang Zoologi, LlPI, Jalan Ir. H. Juanda 9, Bogor, Indonesia 16122 Abstract - Bearded Tomb Bats, TapholollS melanopogoll and T acllates. were recently collected on Wetar, Tanimbar and Kai Islands, eastern Indonesia. Morphological comparisons of skull, dentary, dental and external characters and a univariate and multivariate statistical analyses of 138 specimens, indicated that the animals from Wetar Island were T a. achates. Those from the Tanimbar and Kai Islands were morphologically distinct from both T. melanopogon and T. a. achates, but were closer to the latter taxon. They are herein described as a new subspecies of T. achates, T. achates minor INTRODUCTION more isolated from the other islands in these areas An earlier study of the morphological variation (Kitchener and Maryanto 1993; Kitchener et al. of Bearded Tomb Bats in Nusa Tenggara, 1993b; 1995a,b). Indonesia, by Kitchener et al. (1993a) recognised This paper will describe the morphological the occurrence in that region of two species, variation of the Bearded Tomb Bats from the Taphozous m. meIanopogon Temminck, 1841 and T. southern region of Maluku Tenggara and report on achates Thomas, 1915. The former was found on the taxonomic status of these bats. islands in the Inner Banda Arc (Lombok, Sumbawa, Moyo and Alor), as well as Timor in the Outer Banda Arc. Koopman and Cordon (1992) MATERIAL AND METHODS also report that a specimen of T. meIanopogon exists Measurements from 111 adult specimens used in in the American Museum of Natural History from the previous analysis of morphological variation in Kei (= Kai) Island. Taphozous achates occurred only Taphozous in this region presented in Kitchener et on islands in the Outer Banda Arc (Savu, Roti and al. (1993a) were combined with measurements Semau and possibly also on Timor). from an additional 33 adult specimens from Wetar Kitchener et al. (1993a) noted that while there was Island (9), Kai Besar Island (12) and Selaru Island, little morphological differentiation in T. m. Tanimbar Croup (12) for statistical analysis. The melanopogon among islands in Nusa Tenggara, measurements recorded were the same as those there appeared to be some differentiation among documented in that previous study. However, populations of T. achates. These authors suggest palate length in both this and the previous study that T. m. meIanopogon is Laurasian in origin and was measured from the posterior margin of the may be a relatively recent inhabitant of Nusa palate to the posterior margin of the anterior Tenggara and speculate that '7. achates alone will palatal incisor, and not to the anterior edge of the be found to occur on the smaller Condwanic Cl alveoli as figured in Kitchener et al. (1993a: islands such as Leti, Babar, Tanimbar, Kei (= Kai) figure 1). and Aru". The recent collection of Bearded Tomb The measurements were as follows: CSL, greatest Bats from Wetar, Tanimbar and Kai Islands by staff skull length; IOW, least interorbital breadth; POW, from the Western Australian Museum and postorbital breadth; CW, cranial breadth; MW, Museum Zoologicurn Bogoriense allows for this mastoid width; ZW, zygomatic width; PPL, post speculation to be examined. palatal length; PL, palatal length; OBe, distance Recent studies on morphological variation (and between cochleae; BL, bulla length; CBPL, greatest in some cases of genetic variation) have shown a basial pit length; OL, dentary length; CIBW, Cl tendency for some species of bats that are widely basal breadth; C1C1B, width across C1CI labial distributed in Nusa Tenggara and Maluku surfaces at alveoli; MJM3B, width across M3M3 Tenggara to differentiate morphologically in the labial surfaces at alveoli; C1M3L, maxillary tooth southeastern parts of these provinces, where the row length, from Clalveoli anterior edge to M3 islands in the Inner and Outer Banda Arcs become alveoli posterior edge; M 2L, M 2 crown length; M2W, 214 D.J. Kitchener, A. Suyanto II 1000l<m Figure 1 Locality of Taphozous melanopogon (e) and T. achates (0) used in this study. M2 crown breadth; SVL, tip of snout to anus length; islands which had both sexes and all age classes TVL, distal tip of tail to anus length; EL, ear length; present (Lombok, Sumbawa, Timor, Roti, Wetar, GTW, greatest tragus breadth; RL, radius length; Kai Besar and Selaru (Tanimbar Group). Graphical D3-SMCL, digit 3-5 metacarpal length; D3Pl-2L, inspection of raw data using residual plots from digit 3 phalanx 1-2 length; TL, tibia length; PES, regression analysis gave no indication of pes length. heteroscedasticity. Because of the number of All skull, dentary and dental characters were interactions tested in this analysis the probability measured with vernier callipers to 0.01 mm and level was set at P<O.Ol. external measurements to 0.1 mm. Stepwise Canonical Variate (Discriminant Adult status was recognised and adult age Function) Analysis (DFA) were run for skull, classes determined in the manner described in dentary and dental characters and separately for Kitchener et al. (1993a). external characters after first examining for sexual The effect of sex and island on all characters was dimorphism or age effects. A reduced set of five of examined by standard multiple regressions (where these characters was used in the presented DFA all effects were assessed simultaneously) for the because they provided similar OF plots to the Table 1 Measurements (in mm) for skull, dentary, dental and external body characters of adult Ttphozous a. achates from Wetar Island and T. a. minor subsp. novo from both Yamdena and Kai Besar Islands. X, mean; SD, standard deviation; MIN, minimum; MAX, maximum and N, sample size. GSL IOW POW CW MW ZW PPL PL DBC BL GBPL DL CIBW T. a. achates X 21.66 6.35 4.72 10.00 11.38 13.25 10.36 6.24 2.31 5.02 4.01 17.21 1.29 (Wetar Island) SD 0.39 0.23 0.08 0.19 0.17 0.25 0.19 0.19 0.14 0.14 0.14 0.30 0.07 MIN 21.22 5.95 4.65 9.62 11.12 12.88 10.09 6.05 2.09 4.79 3.85 16.82 1.15 MAX 22.55 6.59 4.89 10.25 11.62 13.71 10.67 6.52 2.51 5.13 4.34 17.76 1.37 N 9 9 9 9 9 8 9 9 9 8 9 9 9 T. a. minor X 20.36 6.25 4.57 9.62 11.00 12.76 9.98 5.82 2.12 4.72 3.71 16.32 1.17 subsp. novo SD 0.21 0.29 0.09 0.09 0.10 0.17 0.13 0.17 0.06 0.09 0.11 0.25 0.07 (Yamdena Island) MIN 19.94 5.82 4.48 9.42 10.88 12.42 9.82 5.43 2.04 4.57 3.49 12.96 1.06 MAX 20.61 6.62 4.73 9.78 11.15 13.01 10.21 6.10 2.23 4.80 3.84 16.65 1.28 N 12 12 12 12 12 12 12 12 12 8 12 12 12 T. a. minor X 20.74 6.21 4.65 9.64 11.09 12.97 10.10 6.02 2.15 4.74 3.85 16.56 1.26 subsp. novo SD 0.25 0.23 0.07 0.10 0.09 0.11 0.23 0.14 0.12 0.08 0.12 0.16 0.06 (Kai Besar Island) MIN 20.43 5.91 4.54 9.42 10.96 12.81 9.75 5.77 2.01 4.61 3.56 16.27 1.20 MAX 21.12 6.61 4.81 9.80 11.25 13.19 10.43 6.27 2.41 4.86 4.07 16.80 1.38 N 12 12 12 12 12 12 12 12 12 12 12 12 12 Indonesian Bearded Tomb Bats 215 larger set of characters. This reduced set of island at P<CJ.OOl, except for postorbital width characters was selected because the sample size of (P=O.013). the smallest island group was less than the total number of characters considered. This reduced set Externals of characters was selected because they provide values that minimise Wilk's Lambda. All analyses Sex and age used the statistical package SPSS PC+. There were no significant associations between sex and age and the external characters. There was, Univariate Statistics however a significant interaction for tail to vent The mean, standard deviation, and range of length between sex and island ( 3.863; measurements of skull, dentary and dental P=O.002). characters of both adult male and adult female TapllOzouS from Wetar, Tanimbar and Kai Island Island are presented In Table 1. Comparable Only snout to vent length, greatest tragus measurements for specimens from other islands in breadth, digit 4 metacarpal length, digit 5 Nusa Tenggara are presented in Kitchener et al. metacarpal length and pes length were not (1993a: table 2). These measurements indicate that significantly associated with island; tail to vent the Tanimbar and Kai individuals were of similar length was the most significantly associated size but the Wetar individuals were generally . variable (F6 88=10.699; P=<O.OOl). larger in skull, dentary and dental measurements. Discriminant function analysis (DFA) Multiple regression analysis Skull, dentary and dental characters Skull, dentary and dental characters Because of the absence of significant sexual This analysis examined the association between dimorphism and the significant association of only the main effects of sex, age and island and the one character (M2 width) with age, the DFA based recorded measurements and the interactions on skull, dentary and dental characters and the 11 between these effects.